1
|
Unda F, de Vries L, Karlen SD, Rainbow J, Zhang C, Bartley LE, Kim H, Ralph J, Mansfield SD. Enhancing monolignol ferulate conjugate levels in poplar lignin via OsFMT1. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:97. [PMID: 39003470 PMCID: PMC11246582 DOI: 10.1186/s13068-024-02544-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 06/25/2024] [Indexed: 07/15/2024]
Abstract
BACKGROUND The phenolic polymer lignin is one of the primary chemical constituents of the plant secondary cell wall. Due to the inherent plasticity of lignin biosynthesis, several phenolic monomers have been shown to be incorporated into the polymer, as long as the monomer can undergo radicalization so it can participate in coupling reactions. In this study, we significantly enhance the level of incorporation of monolignol ferulate conjugates into the lignin polymer to improve the digestibility of lignocellulosic biomass. RESULTS Overexpression of a rice Feruloyl-CoA Monolignol Transferase (FMT), OsFMT1, in hybrid poplar (Populus alba x grandidentata) produced transgenic trees clearly displaying increased cell wall-bound ester-linked ferulate, p-hydroxybenzoate, and p-coumarate, all of which are in the lignin cell wall fraction, as shown by NMR and DFRC. We also demonstrate the use of a novel UV-Vis spectroscopic technique to rapidly screen plants for the presence of both ferulate and p-hydroxybenzoate esters. Lastly we show, via saccharification assays, that the OsFMT1 transgenic p oplars have significantly improved processing efficiency compared to wild-type and Angelica sinensis-FMT-expressing poplars. CONCLUSIONS The findings demonstrate that OsFMT1 has a broad substrate specificity and a higher catalytic efficiency compared to the previously published FMT from Angelica sinensis (AsFMT). Importantly, enhanced wood processability makes OsFMT1 a promising gene to optimize the composition of lignocellulosic biomass.
Collapse
Affiliation(s)
- Faride Unda
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA
| | - Lisanne de Vries
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA
| | - Steven D Karlen
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jordan Rainbow
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Chengcheng Zhang
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Laura E Bartley
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Hoon Kim
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA
- US Department of Agriculture (USDA), Forest Service, Forest Products Laboratory (FPL), Madison, WI, 53726, USA
| | - John Ralph
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Shawn D Mansfield
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA.
- Botany Department, Faculty of Science, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| |
Collapse
|
2
|
Becklin KM, Viele BM, Coleman HD. Nutrient conditions mediate mycorrhizal effects on biomass production and cell wall chemistry in poplar. TREE PHYSIOLOGY 2023; 43:1571-1583. [PMID: 37166359 DOI: 10.1093/treephys/tpad064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 04/13/2023] [Accepted: 05/08/2023] [Indexed: 05/12/2023]
Abstract
Large-scale biofuel production from lignocellulosic feedstock is limited by the financial and environmental costs associated with growing and processing lignocellulosic material and the resilience of these plants to environmental stress. Symbiotic associations with arbuscular (AM) and ectomycorrhizal (EM) fungi represent a potential strategy for expanding feedstock production while reducing nutrient inputs. Comparing AM and EM effects on wood production and chemical composition is a necessary step in developing biofuel feedstocks. Here, we assessed the productivity, biomass allocation and secondary cell wall (SCW) composition of greenhouse-grown Populus tremuloidesMichx. inoculated with either AM or EM fungi. Given the long-term goal of reducing nutrient inputs for biofuel production, we further tested the effects of nutrient availability and nitrogen:phosphorus stoichiometry on mycorrhizal responses. Associations with both AM and EM fungi increased plant biomass by 14-74% depending on the nutrient conditions but had minimal effects on SCW composition. Mycorrhizal plants, especially those inoculated with EM fungi, also allocated a greater portion of their biomass to roots, which could be beneficial in the field where plants are likely to experience both water and nutrient stress. Leaf nutrient content was weakly but positively correlated with wood production in mycorrhizal plants. Surprisingly, phosphorus played a larger role in EM plants compared with AM plants. Relative nitrogen and phosphorus availability were correlated with shifts in SCW composition. For AM associations, the benefit of increased wood biomass may be partially offset by increased lignin content, a trait that affects downstream processing of lignocellulosic tissue for biofuels. By comparing AM and EM effects on the productivity and chemical composition of lignocellulosic tissue, this work links broad functional diversity in mycorrhizal associations to key biofuel traits and highlights the importance of considering both biotic and abiotic factors when developing strategies for sustainable biofuel production.
Collapse
Affiliation(s)
- Katie M Becklin
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, USA
| | - Bethanie M Viele
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, USA
| | - Heather D Coleman
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, USA
| |
Collapse
|
3
|
Balk M, Sofia P, Neffe AT, Tirelli N. Lignin, the Lignification Process, and Advanced, Lignin-Based Materials. Int J Mol Sci 2023; 24:11668. [PMID: 37511430 PMCID: PMC10380785 DOI: 10.3390/ijms241411668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
At a time when environmental considerations are increasingly pushing for the application of circular economy concepts in materials science, lignin stands out as an under-used but promising and environmentally benign building block. This review focuses (A) on understanding what we mean with lignin, i.e., where it can be found and how it is produced in plants, devoting particular attention to the identity of lignols (including ferulates that are instrumental for integrating lignin with cell wall polysaccharides) and to the details of their coupling reactions and (B) on providing an overview how lignin can actually be employed as a component of materials in healthcare and energy applications, finally paying specific attention to the use of lignin in the development of organic shape-memory materials.
Collapse
Affiliation(s)
- Maria Balk
- Institute of Functional Materials for Sustainability, Helmholtz-Zentrum Hereon, Kantstrasse 55, 14513 Teltow, Germany
| | - Pietro Sofia
- Laboratory of Polymers and Biomaterials, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
- The Open University Affiliated Research Centre at the Istituto Italiano di Tecnologia (ARC@IIT), Via Morego 30, 16163 Genova, Italy
| | - Axel T Neffe
- Institute of Functional Materials for Sustainability, Helmholtz-Zentrum Hereon, Kantstrasse 55, 14513 Teltow, Germany
| | - Nicola Tirelli
- Laboratory of Polymers and Biomaterials, Fondazione Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| |
Collapse
|
4
|
Schubert M, Panzarasa G, Burgert I. Sustainability in Wood Products: A New Perspective for Handling Natural Diversity. Chem Rev 2023; 123:1889-1924. [PMID: 36535040 DOI: 10.1021/acs.chemrev.2c00360] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Wood is a renewable resource with excellent qualities and the potential to become a key element of a future bioeconomy. The increasing environmental awareness and drive to achieve sustainability is leading to a resurgence of research on wood materials. Nevertheless, the global climate changes and associated consequences will soon challenge the wood-value chains in several regions (e.g., central Europe). To cope with these challenges, it is necessary to rethink the current practice of wood sourcing and transformation. The goal of this review is to address the intrinsic natural diversity of wood, from its origin to its technological consequences for the present and future manufacturing of wood products. So far, industrial processes have been optimized to repress the variability of wood properties, enabling more efficient processing and production of reliable products. However, the need to preserve biodiversity and the impact of climate change on forests call for new wood processing techniques and green chemistry protocols for wood modification as enabling factors necessary for managing a more diverse wood provision in the future. This article discusses the past developments that have resulted in the current wood value chains and provides a perspective about how natural variability could be turned into an asset for making truly sustainable wood products. After briefly introducing the chemical and structural complexity of wood, the methods conventionally adopted for industrial homogenization and modification of wood are discussed in relation to their evolution toward increased sustainability. Finally, a perspective is given on technological potentials of machine learning techniques and of novel functional wood materials. Here the main message is that through a combination of sustainable forestry, adherence to green chemistry principles and adapted processes based on machine learning, the wood industry could not only overcome current challenges but also thrive in the near future despite the awaiting challenges.
Collapse
Affiliation(s)
- Mark Schubert
- WoodTec Group, Cellulose & Wood Materials, Empa, CH-8600 Dübendorf, Switzerland
| | - Guido Panzarasa
- Wood Materials Science, Institute for Building Materials, ETH Zürich, CH-8093 Zurich, Switzerland
| | - Ingo Burgert
- WoodTec Group, Cellulose & Wood Materials, Empa, CH-8600 Dübendorf, Switzerland.,Wood Materials Science, Institute for Building Materials, ETH Zürich, CH-8093 Zurich, Switzerland
| |
Collapse
|
5
|
Ramakrishna P, Cesarino I. Loosen up! How lignin manipulations affect biomass molecular assembly and deconstruction. PLANT PHYSIOLOGY 2023; 191:3-5. [PMID: 36303327 PMCID: PMC9806552 DOI: 10.1093/plphys/kiac503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Priya Ramakrishna
- Laboratory for Biological Geochemistry, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Igor Cesarino
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
- Synthetic and Systems Biology Center, InovaUSP, Avenida Professor Lucio Martins Rodrigues, São Paulo, Brazil
| |
Collapse
|
6
|
Martin AF, Tobimatsu Y, Lam PY, Matsumoto N, Tanaka T, Suzuki S, Kusumi R, Miyamoto T, Takeda-Kimura Y, Yamamura M, Koshiba T, Osakabe K, Osakabe Y, Sakamoto M, Umezawa T. Lignocellulose molecular assembly and deconstruction properties of lignin-altered rice mutants. PLANT PHYSIOLOGY 2023; 191:70-86. [PMID: 36124989 PMCID: PMC9806629 DOI: 10.1093/plphys/kiac432] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Bioengineering approaches to modify lignin content and structure in plant cell walls have shown promise for facilitating biochemical conversions of lignocellulosic biomass into valuable chemicals. Despite numerous research efforts, however, the effect of altered lignin chemistry on the supramolecular assembly of lignocellulose and consequently its deconstruction in lignin-modified transgenic and mutant plants is not fully understood. In this study, we aimed to close this gap by analyzing lignin-modified rice (Oryza sativa L.) mutants deficient in 5-HYDROXYCONIFERALDEHYDE O-METHYLTRANSFERASE (CAldOMT) and CINNAMYL ALCOHOL DEHYDROGENASE (CAD). A set of rice mutants harboring knockout mutations in either or both OsCAldOMT1 and OsCAD2 was generated in part by genome editing and subjected to comparative cell wall chemical and supramolecular structure analyses. In line with the proposed functions of CAldOMT and CAD in grass lignin biosynthesis, OsCAldOMT1-deficient mutant lines produced altered lignins depleted of syringyl and tricin units and incorporating noncanonical 5-hydroxyguaiacyl units, whereas OsCAD2-deficient mutant lines produced lignins incorporating noncanonical hydroxycinnamaldehyde-derived units. All tested OsCAldOMT1- and OsCAD2-deficient mutants, especially OsCAldOMT1-deficient lines, displayed enhanced cell wall saccharification efficiency. Solid-state nuclear magnetic resonance (NMR) and X-ray diffraction analyses of rice cell walls revealed that both OsCAldOMT1- and OsCAD2 deficiencies contributed to the disruptions of the cellulose crystalline network. Further, OsCAldOMT1 deficiency contributed to the increase of the cellulose molecular mobility more prominently than OsCAD2 deficiency, resulting in apparently more loosened lignocellulose molecular assembly. Such alterations in cell wall chemical and supramolecular structures may in part account for the variations of saccharification performance of the OsCAldOMT1- and OsCAD2-deficient rice mutants.
Collapse
Affiliation(s)
- Andri Fadillah Martin
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Research Center for Genetic Engineering, National Research and Innovation Agency (BRIN), Bogor, 16911, Indonesia
| | - Yuki Tobimatsu
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
| | - Pui Ying Lam
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Center for Crossover Education, Graduate School of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Naoyuki Matsumoto
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
| | - Takuto Tanaka
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
| | - Shiro Suzuki
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan
| | - Ryosuke Kusumi
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Takuji Miyamoto
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Sakeology Center, Niigata University, Niigata, 950-2181, Japan
| | - Yuri Takeda-Kimura
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Masaomi Yamamura
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, 770-8503, Japan
| | - Taichi Koshiba
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- National Agriculture and Food Research Organization, Tsukuba, 305-8517, Japan
| | - Keishi Osakabe
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, 770-8503, Japan
| | - Yuriko Osakabe
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Masahiro Sakamoto
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Toshiaki Umezawa
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji 611-0011, Japan
- Research Unit for Realization of Sustainable Society (RURSS), Kyoto University, Uji, 611-0011, Japan
| |
Collapse
|
7
|
Li J, Hu C, Arreola-Vargas J, Chen K, Yuan JS. Feedstock design for quality biomaterials. Trends Biotechnol 2022; 40:1535-1549. [PMID: 36273927 DOI: 10.1016/j.tibtech.2022.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 11/11/2022]
Abstract
Feedstock design is crucial for lignocellulosic biomass use. Current strategies for feedstock design cannot be readily applied to improve the quality of biomass-based materials, limiting the sustainability and economics of lignocellulosic biorefineries. Recent studies have advanced the understanding of biomass structure-property relationships and discovered several characteristics, such as molecular weight, uniformity, linkage profile, and functional groups, that are critical for manufacturing diverse quality biomaterials. These discoveries call for fundamentally different strategies for feedstock development. Such strategies need to rediscover the roles of monolignol biosynthesis enzymes and leverage lignin polymerization enzymes to achieve precise control of lignin molecular structure. These innovations could transform biomass into feedstock for high-quality biomaterials, addressing essential environmental challenges and empowering the bioeconomy.
Collapse
Affiliation(s)
- Jinghao Li
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Cheng Hu
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
| | - Jorge Arreola-Vargas
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
| | - Kainan Chen
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
| | - Joshua S Yuan
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
| |
Collapse
|
8
|
De Meester B, Vanholme R, Mota T, Boerjan W. Lignin engineering in forest trees: From gene discovery to field trials. PLANT COMMUNICATIONS 2022; 3:100465. [PMID: 36307984 PMCID: PMC9700206 DOI: 10.1016/j.xplc.2022.100465] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/10/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Wood is an abundant and renewable feedstock for the production of pulp, fuels, and biobased materials. However, wood is recalcitrant toward deconstruction into cellulose and simple sugars, mainly because of the presence of lignin, an aromatic polymer that shields cell-wall polysaccharides. Hence, numerous research efforts have focused on engineering lignin amount and composition to improve wood processability. Here, we focus on results that have been obtained by engineering the lignin biosynthesis and branching pathways in forest trees to reduce cell-wall recalcitrance, including the introduction of exotic lignin monomers. In addition, we draw general conclusions from over 20 years of field trial research with trees engineered to produce less or altered lignin. We discuss possible causes and solutions for the yield penalty that is often associated with lignin engineering in trees. Finally, we discuss how conventional and new breeding strategies can be combined to develop elite clones with desired lignin properties. We conclude this review with priorities for the development of commercially relevant lignin-engineered trees.
Collapse
Affiliation(s)
- Barbara De Meester
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Ruben Vanholme
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Thatiane Mota
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Wout Boerjan
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.
| |
Collapse
|
9
|
Recent Advancements and Challenges in Lignin Valorization: Green Routes towards Sustainable Bioproducts. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27186055. [PMID: 36144795 PMCID: PMC9500909 DOI: 10.3390/molecules27186055] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/10/2022] [Accepted: 09/13/2022] [Indexed: 11/27/2022]
Abstract
The aromatic hetero-polymer lignin is industrially processed in the paper/pulp and lignocellulose biorefinery, acting as a major energy source. It has been proven to be a natural resource for useful bioproducts; however, its depolymerization and conversion into high-value-added chemicals is the major challenge due to the complicated structure and heterogeneity. Conversely, the various pre-treatments techniques and valorization strategies offers a potential solution for developing a biomass-based biorefinery. Thus, the current review focus on the new isolation techniques for lignin, various pre-treatment approaches and biocatalytic methods for the synthesis of sustainable value-added products. Meanwhile, the challenges and prospective for the green synthesis of various biomolecules via utilizing the complicated hetero-polymer lignin are also discussed.
Collapse
|
10
|
De Meester B, Oyarce P, Vanholme R, Van Acker R, Tsuji Y, Vangeel T, Van den Bosch S, Van Doorsselaere J, Sels B, Ralph J, Boerjan W. Engineering Curcumin Biosynthesis in Poplar Affects Lignification and Biomass Yield. FRONTIERS IN PLANT SCIENCE 2022; 13:943349. [PMID: 35860528 PMCID: PMC9289561 DOI: 10.3389/fpls.2022.943349] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/14/2022] [Indexed: 06/02/2023]
Abstract
Lignocellulosic biomass is recalcitrant toward deconstruction into simple sugars mainly due to the presence of lignin. By engineering plants to partially replace traditional lignin monomers with alternative ones, lignin degradability and extractability can be enhanced. Previously, the alternative monomer curcumin has been successfully produced and incorporated into lignified cell walls of Arabidopsis by the heterologous expression of DIKETIDE-CoA SYNTHASE (DCS) and CURCUMIN SYNTHASE2 (CURS2). The resulting transgenic plants did not suffer from yield penalties and had an increased saccharification yield after alkaline pretreatment. Here, we translated this strategy into the bio-energy crop poplar. Via the heterologous expression of DCS and CURS2 under the control of the secondary cell wall CELLULOSE SYNTHASE A8-B promoter (ProCesA8-B), curcumin was also produced and incorporated into the lignified cell walls of poplar. ProCesA8-B:DCS_CURS2 transgenic poplars, however, suffered from shoot-tip necrosis and yield penalties. Compared to that of the wild-type (WT), the wood of transgenic poplars had 21% less cellulose, 28% more matrix polysaccharides, 23% more lignin and a significantly altered lignin composition. More specifically, ProCesA8-B:DCS_CURS2 lignin had a reduced syringyl/guaiacyl unit (S/G) ratio, an increased frequency of p-hydroxyphenyl (H) units, a decreased frequency of p-hydroxybenzoates and a higher fraction of phenylcoumaran units. Without, or with alkaline or hot water pretreatment, the saccharification efficiency of the transgenic lines was equal to that of the WT. These differences in (growth) phenotype illustrate that translational research in crops is essential to assess the value of an engineering strategy for applications. Further fine-tuning of this research strategy (e.g., by using more specific promoters or by translating this strategy to other crops such as maize) might lead to transgenic bio-energy crops with cell walls more amenable to deconstruction without settling in yield.
Collapse
Affiliation(s)
- Barbara De Meester
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Paula Oyarce
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Ruben Vanholme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Rebecca Van Acker
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Yukiko Tsuji
- Department of Biochemistry, University of Wisconsin, Madison, WI, United States
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, WI, United States
| | - Thijs Vangeel
- Center for Sustainable Catalysis and Engineering, KU Leuven, Leuven, Belgium
| | | | | | - Bert Sels
- Center for Sustainable Catalysis and Engineering, KU Leuven, Leuven, Belgium
| | - John Ralph
- Department of Biochemistry, University of Wisconsin, Madison, WI, United States
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, WI, United States
| | - Wout Boerjan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| |
Collapse
|
11
|
Unda F, Mottiar Y, Mahon EL, Karlen SD, Kim KH, Loqué D, Eudes A, Ralph J, Mansfield SD. A new approach to zip-lignin: 3,4-dihydroxybenzoate is compatible with lignification. THE NEW PHYTOLOGIST 2022; 235:234-246. [PMID: 35377486 PMCID: PMC9325543 DOI: 10.1111/nph.18136] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/17/2022] [Indexed: 06/02/2023]
Abstract
Renewed interests in the development of bioenergy, biochemicals, and biomaterials have elicited new strategies for engineering the lignin of biomass feedstock plants. This study shows, for the first time, that 3,4-dihydroxybenzoate (DHB) is compatible with the radical coupling reactions that assemble polymeric lignin in plants. We introduced a bacterial 3-dehydroshikimate dehydratase into hybrid poplar (Populus alba × grandidentata) to divert carbon flux away from the shikimate pathway, which lies upstream of lignin biosynthesis. Transgenic poplar wood had up to 33% less lignin with p-hydroxyphenyl units comprising as much as 10% of the lignin. Mild alkaline hydrolysis of transgenic wood released fewer ester-linked p-hydroxybenzoate groups than control trees, and revealed the novel incorporation of cell-wall-bound DHB, as well as glycosides of 3,4-dihydroxybenzoic acid (DHBA). Two-dimensional nuclear magnetic resonance (2D-NMR) analysis uncovered DHBA-derived benzodioxane structures suggesting that DHB moieties were integrated into the lignin polymer backbone. In addition, up to 40% more glucose was released from transgenic wood following ionic liquid pretreatment and enzymatic hydrolysis. This work highlights the potential of diverting carbon flux from the shikimate pathway for lignin engineering and describes a new type of 'zip-lignin' derived from the incorporation of DHB into poplar lignin.
Collapse
Affiliation(s)
- Faride Unda
- Department of Wood ScienceUniversity of British Columbia2424 Main MallVancouverBCV6T 1Z4Canada
- Department of EnergyGreat Lakes Bioenergy Research CenterWisconsin Energy InstituteUniversity of Wisconsin‐Madison1552 University AvenueMadisonWI53726USA
| | - Yaseen Mottiar
- Department of Wood ScienceUniversity of British Columbia2424 Main MallVancouverBCV6T 1Z4Canada
- Department of EnergyGreat Lakes Bioenergy Research CenterWisconsin Energy InstituteUniversity of Wisconsin‐Madison1552 University AvenueMadisonWI53726USA
| | - Elizabeth L. Mahon
- Department of Wood ScienceUniversity of British Columbia2424 Main MallVancouverBCV6T 1Z4Canada
- Department of EnergyGreat Lakes Bioenergy Research CenterWisconsin Energy InstituteUniversity of Wisconsin‐Madison1552 University AvenueMadisonWI53726USA
| | - Steven D. Karlen
- Department of EnergyGreat Lakes Bioenergy Research CenterWisconsin Energy InstituteUniversity of Wisconsin‐Madison1552 University AvenueMadisonWI53726USA
- Department of BiochemistryUniversity of Wisconsin‐Madison433 Babcock DriveMadisonWI53706USA
| | - Kwang Ho Kim
- Department of Wood ScienceUniversity of British Columbia2424 Main MallVancouverBCV6T 1Z4Canada
- Clean Energy Research CenterKorea Institute of Science and TechnologySeoul02792Korea
| | - Dominique Loqué
- Joint BioEnergy Institute5885 Hollis StreetEmeryvilleCA94608USA
| | - Aymerick Eudes
- Joint BioEnergy Institute5885 Hollis StreetEmeryvilleCA94608USA
- Environmental Genomics and Systems Biology DivisionLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - John Ralph
- Department of EnergyGreat Lakes Bioenergy Research CenterWisconsin Energy InstituteUniversity of Wisconsin‐Madison1552 University AvenueMadisonWI53726USA
- Department of BiochemistryUniversity of Wisconsin‐Madison433 Babcock DriveMadisonWI53706USA
| | - Shawn D. Mansfield
- Department of Wood ScienceUniversity of British Columbia2424 Main MallVancouverBCV6T 1Z4Canada
- Department of EnergyGreat Lakes Bioenergy Research CenterWisconsin Energy InstituteUniversity of Wisconsin‐Madison1552 University AvenueMadisonWI53726USA
| |
Collapse
|
12
|
Zhuo C, Wang X, Docampo-Palacios M, Sanders BC, Engle NL, Tschaplinski TJ, Hendry JI, Maranas CD, Chen F, Dixon RA. Developmental changes in lignin composition are driven by both monolignol supply and laccase specificity. SCIENCE ADVANCES 2022; 8:eabm8145. [PMID: 35263134 PMCID: PMC8906750 DOI: 10.1126/sciadv.abm8145] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/17/2022] [Indexed: 05/25/2023]
Abstract
The factors controlling lignin composition remain unclear. Catechyl (C)-lignin is a homopolymer of caffeyl alcohol with unique properties as a biomaterial and precursor of industrial chemicals. The lignin synthesized in the seed coat of Cleome hassleriana switches from guaiacyl (G)- to C-lignin at around 12 to 14 days after pollination (DAP), associated with a rerouting of the monolignol pathway. Lack of synthesis of caffeyl alcohol limits C-lignin formation before around 12 DAP, but coniferyl alcohol is still synthesized and highly accumulated after 14 DAP. We propose a model in which, during C-lignin biosynthesis, caffeyl alcohol noncompetitively inhibits oxidation of coniferyl alcohol by cell wall laccases, a process that might limit movement of coniferyl alcohol to the apoplast. Developmental changes in both substrate availability and laccase specificity together account for the metabolic fates of G- and C-monolignols in the Cleome seed coat.
Collapse
Affiliation(s)
- Chunliu Zhuo
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xin Wang
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Maite Docampo-Palacios
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
| | - Brian C. Sanders
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Nancy L. Engle
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Timothy J. Tschaplinski
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - John I. Hendry
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Costas D. Maranas
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Fang Chen
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
13
|
de Vries L, MacKay HA, Smith RA, Mottiar Y, Karlen SD, Unda F, Muirragui E, Bingman C, Vander Meulen K, Beebe ET, Fox BG, Ralph J, Mansfield SD. pHBMT1, a BAHD-family monolignol acyltransferase, mediates lignin acylation in poplar. PLANT PHYSIOLOGY 2022; 188:1014-1027. [PMID: 34977949 PMCID: PMC8825253 DOI: 10.1093/plphys/kiab546] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/26/2021] [Indexed: 05/13/2023]
Abstract
Poplar (Populus) lignin is naturally acylated with p-hydroxybenzoate ester moieties. However, the enzyme(s) involved in the biosynthesis of the monolignol-p-hydroxybenzoates have remained largely unknown. Here, we performed an in vitro screen of the Populus trichocarpa BAHD acyltransferase superfamily (116 genes) using a wheatgerm cell-free translation system and found five enzymes capable of producing monolignol-p-hydroxybenzoates. We then compared the transcript abundance of the five corresponding genes with p-hydroxybenzoate concentrations using naturally occurring unrelated genotypes of P. trichocarpa and revealed a positive correlation between the expression of p-hydroxybenzoyl-CoA monolig-nol transferase (pHBMT1, Potri.001G448000) and p-hydroxybenzoate levels. To test whether pHBMT1 is responsible for the biosynthesis of monolignol-p-hydroxybenzoates, we overexpressed pHBMT1 in hybrid poplar (Populus alba × P. grandidentata) (35S::pHBMT1 and C4H::pHBMT1). Using three complementary analytical methods, we showed that there was an increase in soluble monolignol-p-hydroxybenzoates and cell-wall-bound monolignol-p-hydroxybenzoates in the poplar transgenics. As these pendent groups are ester-linked, saponification releases p-hydroxybenzoate, a precursor to parabens that are used in pharmaceuticals and cosmetics. This identified gene could therefore be used to engineer lignocellulosic biomass with increased value for emerging biorefinery strategies.
Collapse
Affiliation(s)
- Lisanne de Vries
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
| | - Heather A MacKay
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Rebecca A Smith
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Yaseen Mottiar
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
| | - Steven D Karlen
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Faride Unda
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
| | - Emilia Muirragui
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Craig Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Kirk Vander Meulen
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Emily T Beebe
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Brian G Fox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - John Ralph
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Shawn D Mansfield
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
- Author for communication:
| |
Collapse
|
14
|
Mahon EL, de Vries L, Jang SK, Middar S, Kim H, Unda F, Ralph J, Mansfield SD. Exogenous chalcone synthase expression in developing poplar xylem incorporates naringenin into lignins. PLANT PHYSIOLOGY 2022; 188:984-996. [PMID: 34718804 PMCID: PMC8825309 DOI: 10.1093/plphys/kiab499] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 09/30/2021] [Indexed: 05/03/2023]
Abstract
Lignin, a polyphenolic polymer, is a major chemical constituent of the cell walls of terrestrial plants. The biosynthesis of lignin is a highly plastic process, as highlighted by an increasing number of noncanonical monomers that have been successfully identified in an array of plants. Here, we engineered hybrid poplar (Populus alba x grandidentata) to express chalcone synthase 3 (MdCHS3) derived from apple (Malus domestica) in lignifying xylem. Transgenic trees displayed an accumulation of the flavonoid naringenin in xylem methanolic extracts not inherently observed in wild-type trees. Nuclear magnetic resonance analysis revealed the presence of naringenin in the extract-free, cellulase-treated xylem lignin of MdCHS3-poplar, indicating the incorporation of this flavonoid-derived compound into poplar secondary cell wall lignins. The transgenic trees also displayed lower total cell wall lignin content and increased cell wall carbohydrate content and performed significantly better in limited saccharification assays than their wild-type counterparts.
Collapse
Affiliation(s)
- Elizabeth L Mahon
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, Canada
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, Wisconsin, USA
| | - Lisanne de Vries
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, Canada
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, Wisconsin, USA
| | - Soo-Kyeong Jang
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, Canada
| | - Sandeep Middar
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, Canada
| | - Hoon Kim
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, Wisconsin, USA
| | - Faride Unda
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, Canada
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, Wisconsin, USA
| | - John Ralph
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Shawn D Mansfield
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, Canada
- US Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, Wisconsin, USA
- Author for communication:
| |
Collapse
|
15
|
Motto M, Sahay S. Energy plants (crops): potential natural and future designer plants. HANDBOOK OF BIOFUELS 2022:73-114. [DOI: 10.1016/b978-0-12-822810-4.00004-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
|
16
|
Lapierre C, Sibout R, Laurans F, Lesage-Descauses MC, Déjardin A, Pilate G. p-Coumaroylation of poplar lignins impacts lignin structure and improves wood saccharification. PLANT PHYSIOLOGY 2021; 187:1374-1386. [PMID: 34618081 PMCID: PMC8566233 DOI: 10.1093/plphys/kiab359] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/16/2021] [Indexed: 05/03/2023]
Abstract
The enzymatic hydrolysis of cellulose into glucose, referred to as saccharification, is severely hampered by lignins. Here, we analyzed transgenic poplars (Populus tremula × Populus alba) expressing the Brachypodium (Brachypodium distachyon) p-coumaroyl-Coenzyme A monolignol transferase 1 (BdPMT1) gene driven by the Arabidopsis (Arabidopsis thaliana) Cinnamate 4-Hydroxylase (AtC4H) promoter in the wild-type (WT) line and in a line overexpressing the Arabidopsis Ferulate 5-Hydroxylase (AtF5H). BdPMT1 encodes a transferase which catalyzes the acylation of monolignols by p-coumaric acid (pCA). Several BdPMT1-OE/WT and BdPMT1-OE/AtF5H-OE lines were grown in the greenhouse, and BdPMT1 expression in xylem was confirmed by RT-PCR. Analyses of poplar stem cell walls (CWs) and of the corresponding purified dioxan lignins (DLs) revealed that BdPMT1-OE lignins were as p-coumaroylated as lignins from C3 grass straws. For some transformants, pCA levels reached 11 mg·g-1 CW and 66 mg·g-1 DL, exceeding levels in Brachypodium or wheat (Triticum aestivum) samples. This unprecedentedly high lignin p-coumaroylation affected neither poplar growth nor stem lignin content. Interestingly, p-coumaroylation of poplar lignins was not favored in BdPMT1-OE/AtF5H-OE transgenic lines despite their high frequency of syringyl units. However, lignins of all BdPMT1-OE lines were structurally modified, with an increase of terminal unit with free phenolic groups. Relative to controls, this increase argues for a reduced polymerization degree of BdPMT1-OE lignins and makes them more soluble in cold NaOH solution. The p-coumaroylation of poplar samples improved the saccharification yield of alkali-pretreated CW, demonstrating that the genetically driven p-coumaroylation of lignins is a promising strategy to make wood lignins more susceptible to alkaline treatments used during the industrial processing of lignocellulosics.
Collapse
Affiliation(s)
| | | | | | | | | | - Gilles Pilate
- INRAE, ONF, BioForA, Orléans, France
- Author for communication:
| |
Collapse
|
17
|
De Meester B, Vanholme R, de Vries L, Wouters M, Van Doorsselaere J, Boerjan W. Vessel- and ray-specific monolignol biosynthesis as an approach to engineer fiber-hypolignification and enhanced saccharification in poplar. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:752-765. [PMID: 34403547 DOI: 10.1111/tpj.15468] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/06/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Lignin is one of the main factors determining recalcitrance to processing of lignocellulosic biomass towards bio-based materials and fuels. Consequently, wood of plants engineered for low lignin content is typically more amenable to processing. However, lignin-modified plants often exhibit collapsed vessels and associated growth defects. Vessel-specific reintroduction of lignin biosynthesis in dwarfed low-lignin cinnamoyl-CoA reductase1 (ccr1) Arabidopsis mutants using the ProSNBE:AtCCR1 construct overcame the yield penalty while maintaining high saccharification yields, and showed that monolignols can be transported between the different xylem cells acting as 'good neighbors' in Arabidopsis. Here, we translated this research into the bio-energy crop poplar. By expressing ProSNBE:AtCCR1 into CRISPR/Cas9-generated ccr2 poplars, we aimed for vessel-specific lignin biosynthesis to: (i) achieve growth restoration while maintaining high saccharification yields; and (ii) study the existence of 'good neighbors' in poplar wood. Analyzing the resulting ccr2 ProSNBE:AtCCR1 poplars showed that vessels and rays act as good neighbors for lignification in poplar. If sufficient monolignols are produced by these cells, monolignols migrate over multiple cell layers, resulting in a restoration of the lignin amount to wild-type levels. If the supply of monolignols is limited, the monolignols are incorporated into the cell walls of the vessels and rays producing them and their adjoining cells resulting in fiber hypolignification. One such fiber-hypolignified line had 18% less lignin and, despite its small yield penalty, had an increase of up to 71% in sugar release on a plant base upon saccharification.
Collapse
Affiliation(s)
- Barbara De Meester
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| | - Ruben Vanholme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| | - Lisanne de Vries
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| | - Marlies Wouters
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| | - Jan Van Doorsselaere
- Higher Institute for Nursing and Biotechnology, VIVES University College, Wilgenstraat 32, Roeselare, 8800, Belgium
| | - Wout Boerjan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent, 9052, Belgium
| |
Collapse
|
18
|
Yu S, Bekkering CS, Tian L. Metabolic engineering in woody plants: challenges, advances, and opportunities. ABIOTECH 2021; 2:299-313. [PMID: 36303882 PMCID: PMC9590576 DOI: 10.1007/s42994-021-00054-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/06/2021] [Indexed: 06/16/2023]
Abstract
Woody plant species represent an invaluable reserve of biochemical diversity to which metabolic engineering can be applied to satisfy the need for commodity and specialty chemicals, pharmaceuticals, and renewable energy. Woody plants are particularly promising for this application due to their low input needs, high biomass, and immeasurable ecosystem services. However, existing challenges have hindered their widespread adoption in metabolic engineering efforts, such as long generation times, large and highly heterozygous genomes, and difficulties in transformation and regeneration. Recent advances in omics approaches, systems biology modeling, and plant transformation and regeneration methods provide effective approaches in overcoming these outstanding challenges. Promises brought by developments in this space are steadily opening the door to widespread metabolic engineering of woody plants to meet the global need for a wide range of sustainably sourced chemicals and materials.
Collapse
Affiliation(s)
- Shu Yu
- Department of Plant Sciences, Mail Stop 3, University of California, Davis, CA 95616 USA
| | - Cody S. Bekkering
- Department of Plant Sciences, Mail Stop 3, University of California, Davis, CA 95616 USA
| | - Li Tian
- Department of Plant Sciences, Mail Stop 3, University of California, Davis, CA 95616 USA
| |
Collapse
|
19
|
de Vries L, Guevara-Rozo S, Cho M, Liu LY, Renneckar S, Mansfield SD. Tailoring renewable materials via plant biotechnology. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:167. [PMID: 34353358 PMCID: PMC8344217 DOI: 10.1186/s13068-021-02010-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/06/2021] [Indexed: 05/03/2023]
Abstract
Plants inherently display a rich diversity in cell wall chemistry, as they synthesize an array of polysaccharides along with lignin, a polyphenolic that can vary dramatically in subunit composition and interunit linkage complexity. These same cell wall chemical constituents play essential roles in our society, having been isolated by a variety of evolving industrial processes and employed in the production of an array of commodity products to which humans are reliant. However, these polymers are inherently synthesized and intricately packaged into complex structures that facilitate plant survival and adaptation to local biogeoclimatic regions and stresses, not for ease of deconstruction and commercial product development. Herein, we describe evolving techniques and strategies for altering the metabolic pathways related to plant cell wall biosynthesis, and highlight the resulting impact on chemistry, architecture, and polymer interactions. Furthermore, this review illustrates how these unique targeted cell wall modifications could significantly extend the number, diversity, and value of products generated in existing and emerging biorefineries. These modifications can further target the ability for processing of engineered wood into advanced high performance materials. In doing so, we attempt to illuminate the complex connection on how polymer chemistry and structure can be tailored to advance renewable material applications, using all the chemical constituents of plant-derived biopolymers, including pectins, hemicelluloses, cellulose, and lignins.
Collapse
Affiliation(s)
- Lisanne de Vries
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin - Madison, Madison, WI , 53726, USA
| | - Sydne Guevara-Rozo
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - MiJung Cho
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Li-Yang Liu
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Scott Renneckar
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Shawn D Mansfield
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
- US Department of Energy (DOE) Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, University of Wisconsin - Madison, Madison, WI , 53726, USA.
| |
Collapse
|
20
|
Hiraide H, Tobimatsu Y, Yoshinaga A, Lam PY, Kobayashi M, Matsushita Y, Fukushima K, Takabe K. Localised laccase activity modulates distribution of lignin polymers in gymnosperm compression wood. THE NEW PHYTOLOGIST 2021; 230:2186-2199. [PMID: 33570753 PMCID: PMC8252379 DOI: 10.1111/nph.17264] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/03/2021] [Indexed: 05/26/2023]
Abstract
The woody stems of coniferous gymnosperms produce specialised compression wood to adjust the stem growth orientation in response to gravitropic stimulation. During this process, tracheids develop a compression-wood-specific S2 L cell wall layer with lignins highly enriched with p-hydroxyphenyl (H)-type units derived from H-type monolignol, whereas lignins produced in the cell walls of normal wood tracheids are exclusively composed of guaiacyl (G)-type units from G-type monolignol with a trace amount of H-type units. We show that laccases, a class of lignin polymerisation enzymes, play a crucial role in the spatially organised polymerisation of H-type and G-type monolignols during compression wood formation in Japanese cypress (Chamaecyparis obtusa). We performed a series of chemical-probe-aided imaging analysis on C. obtusa compression wood cell walls, together with gene expression, protein localisation and enzymatic assays of C. obtusa laccases. Our data indicated that CoLac1 and CoLac3 with differential oxidation activities towards H-type and G-type monolignols were precisely localised to distinct cell wall layers in which H-type and G-type lignin units were preferentially produced during the development of compression wood tracheids. We propose that, not only the spatial localisation of laccases, but also their biochemical characteristics dictate the spatial patterning of lignin polymerisation in gymnosperm compression wood.
Collapse
Affiliation(s)
- Hideto Hiraide
- Graduate School of AgricultureKyoto UniversityKitashirakawa‐oiwakechoKyoto606‐8502Japan
- Research Institute for Sustainable HumanosphereKyoto UniversityGokasho, Uji611‐0011Japan
| | - Yuki Tobimatsu
- Research Institute for Sustainable HumanosphereKyoto UniversityGokasho, Uji611‐0011Japan
| | - Arata Yoshinaga
- Graduate School of AgricultureKyoto UniversityKitashirakawa‐oiwakechoKyoto606‐8502Japan
| | - Pui Ying Lam
- Research Institute for Sustainable HumanosphereKyoto UniversityGokasho, Uji611‐0011Japan
| | - Masaru Kobayashi
- Graduate School of AgricultureKyoto UniversityKitashirakawa‐oiwakechoKyoto606‐8502Japan
| | - Yasuyuki Matsushita
- Graduate School of Bioagricultural SciencesNagoya UniversityFuro‐choNagoya464‐8601Japan
| | - Kazuhiko Fukushima
- Graduate School of Bioagricultural SciencesNagoya UniversityFuro‐choNagoya464‐8601Japan
| | - Keiji Takabe
- Graduate School of AgricultureKyoto UniversityKitashirakawa‐oiwakechoKyoto606‐8502Japan
| |
Collapse
|
21
|
Lin CY, Donohoe BS, Bomble YJ, Yang H, Yunes M, Sarai NS, Shollenberger T, Decker SR, Chen X, McCann MC, Tucker MP, Wei H, Himmel ME. Iron incorporation both intra- and extra-cellularly improves the yield and saccharification of switchgrass (Panicum virgatum L.) biomass. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:55. [PMID: 33663584 PMCID: PMC7931346 DOI: 10.1186/s13068-021-01891-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Pretreatments are commonly used to facilitate the deconstruction of lignocellulosic biomass to its component sugars and aromatics. Previously, we showed that iron ions can be used as co-catalysts to reduce the severity of dilute acid pretreatment of biomass. Transgenic iron-accumulating Arabidopsis and rice plants exhibited higher iron content in grains, increased biomass yield, and importantly, enhanced sugar release from the biomass. RESULTS In this study, we used intracellular ferritin (FerIN) alone and in combination with an improved version of cell wall-bound carbohydrate-binding module fused iron-binding peptide (IBPex) specifically targeting switchgrass, a bioenergy crop species. The FerIN switchgrass improved by 15% in height and 65% in yield, whereas the FerIN/IBPex transgenics showed enhancement up to 30% in height and 115% in yield. The FerIN and FerIN/IBPex switchgrass had 27% and 51% higher in planta iron accumulation than the empty vector (EV) control, respectively, under normal growth conditions. Improved pretreatability was observed in FerIN switchgrass (~ 14% more glucose release than the EV), and the FerIN/IBPex plants showed further enhancement in glucose release up to 24%. CONCLUSIONS We conclude that this iron-accumulating strategy can be transferred from model plants and applied to bioenergy crops, such as switchgrass. The intra- and extra-cellular iron incorporation approach improves biomass pretreatability and digestibility, providing upgraded feedstocks for the production of biofuels and bioproducts.
Collapse
Affiliation(s)
- Chien-Yuan Lin
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608 USA
- Present Address: Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Haibing Yang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 USA
- Present Address: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Manal Yunes
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Nicholas S. Sarai
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 USA
| | - Todd Shollenberger
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Stephen R. Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Xiaowen Chen
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Maureen C. McCann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 USA
| | - Melvin P. Tucker
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| |
Collapse
|
22
|
Ferreira SS, Antunes MS. Re-engineering Plant Phenylpropanoid Metabolism With the Aid of Synthetic Biosensors. FRONTIERS IN PLANT SCIENCE 2021; 12:701385. [PMID: 34603348 PMCID: PMC8481569 DOI: 10.3389/fpls.2021.701385] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/23/2021] [Indexed: 05/03/2023]
Abstract
Phenylpropanoids comprise a large class of specialized plant metabolites with many important applications, including pharmaceuticals, food nutrients, colorants, fragrances, and biofuels. Therefore, much effort has been devoted to manipulating their biosynthesis to produce high yields in a more controlled manner in microbial and plant systems. However, current strategies are prone to significant adverse effects due to pathway complexity, metabolic burden, and metabolite bioactivity, which still hinder the development of tailor-made phenylpropanoid biofactories. This gap could be addressed by the use of biosensors, which are molecular devices capable of sensing specific metabolites and triggering a desired response, as a way to sense the pathway's metabolic status and dynamically regulate its flux based on specific signals. Here, we provide a brief overview of current research on synthetic biology and metabolic engineering approaches to control phenylpropanoid synthesis and phenylpropanoid-related biosensors, advocating for the use of biosensors and genetic circuits as a step forward in plant synthetic biology to develop autonomously-controlled phenylpropanoid-producing plant biofactories.
Collapse
|
23
|
Perkins ML, Schuetz M, Unda F, Smith RA, Sibout R, Hoffmann NJ, Wong DCJ, Castellarin SD, Mansfield SD, Samuels L. Dwarfism of high-monolignol Arabidopsis plants is rescued by ectopic LACCASE overexpression. PLANT DIRECT 2020; 4:e00265. [PMID: 33005856 PMCID: PMC7520647 DOI: 10.1002/pld3.265] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/24/2020] [Accepted: 08/14/2020] [Indexed: 05/24/2023]
Abstract
Lignin is a key secondary cell wall chemical constituent, and is both a barrier to biomass utilization and a potential source of bioproducts. The Arabidopsis transcription factors MYB58 and MYB63 have been shown to upregulate gene expression of the general phenylpropanoid and monolignol biosynthetic pathways. The overexpression of these genes also results in dwarfism. The vascular integrity, soluble phenolic profiles, cell wall lignin, and transcriptomes associated with these MYB-overexpressing lines were characterized. Plants with high expression of MYB58 and MYB63 had increased ectopic lignin and the xylem vessels were regular and open, suggesting that the stunted growth is not associated with loss of vascular conductivity. MYB58 and MYB63 overexpression lines had characteristic soluble phenolic profiles with large amounts of monolignol glucosides and sinapoyl esters, but decreased flavonoids. Because loss of function lac4 lac17 mutants also accumulate monolignol glucosides, we hypothesized that LACCASE overexpression might decrease monolignol glucoside levels in the MYB-overexpressing plant lines. When laccases related to lignification (LAC4 or LAC17) were co-overexpressed with MYB63 or MYB58, the dwarf phenotype was rescued. Moreover, the overexpression of either LAC4 or LAC17 led to wild-type monolignol glucoside levels, as well as wild-type lignin levels in the rescued plants. Transcriptomes of the rescued double MYB63-OX/LAC17-OX overexpression lines showed elevated, but attenuated, expression of the MYB63 gene itself and the direct transcriptional targets of MYB63. Contrasting the dwarfism from overabundant monolignol production with dwarfism from lignin mutants provides insight into some of the proposed mechanisms of lignin modification-induced dwarfism.
Collapse
Affiliation(s)
| | - Mathias Schuetz
- Department of BotanyUniversity of British ColumbiaVancouverCanada
| | - Faride Unda
- Department of Wood ScienceUniversity of British ColumbiaVancouverCanada
| | - Rebecca A. Smith
- Department of BotanyUniversity of British ColumbiaVancouverCanada
- Department of Energy's Great Lakes Bioenergy Research CenterDepartment of BiochemistryUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Richard Sibout
- Department of BotanyUniversity of British ColumbiaVancouverCanada
- UR1268 BIA (Biopolymères Interactions Assemblages)INRANantesFrance
| | | | | | | | | | - Lacey Samuels
- Department of BotanyUniversity of British ColumbiaVancouverCanada
| |
Collapse
|
24
|
Gigli-Bisceglia N, Engelsdorf T, Hamann T. Plant cell wall integrity maintenance in model plants and crop species-relevant cell wall components and underlying guiding principles. Cell Mol Life Sci 2020; 77:2049-2077. [PMID: 31781810 PMCID: PMC7256069 DOI: 10.1007/s00018-019-03388-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 10/28/2019] [Accepted: 11/19/2019] [Indexed: 02/06/2023]
Abstract
The walls surrounding the cells of all land-based plants provide mechanical support essential for growth and development as well as protection from adverse environmental conditions like biotic and abiotic stress. Composition and structure of plant cell walls can differ markedly between cell types, developmental stages and species. This implies that wall composition and structure are actively modified during biological processes and in response to specific functional requirements. Despite extensive research in the area, our understanding of the regulatory processes controlling active and adaptive modifications of cell wall composition and structure is still limited. One of these regulatory processes is the cell wall integrity maintenance mechanism, which monitors and maintains the functional integrity of the plant cell wall during development and interaction with environment. It is an important element in plant pathogen interaction and cell wall plasticity, which seems at least partially responsible for the limited success that targeted manipulation of cell wall metabolism has achieved so far. Here, we provide an overview of the cell wall polysaccharides forming the bulk of plant cell walls in both monocotyledonous and dicotyledonous plants and the effects their impairment can have. We summarize our current knowledge regarding the cell wall integrity maintenance mechanism and discuss that it could be responsible for several of the mutant phenotypes observed.
Collapse
Affiliation(s)
- Nora Gigli-Bisceglia
- Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, 6708 PB, The Netherlands
| | - Timo Engelsdorf
- Division of Plant Physiology, Department of Biology, Philipps University of Marburg, 35043, Marburg, Germany
| | - Thorsten Hamann
- Institute for Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 5 Høgskoleringen, 7491, Trondheim, Norway.
| |
Collapse
|
25
|
Simões MS, Carvalho GG, Ferreira SS, Hernandes-Lopes J, de Setta N, Cesarino I. Genome-wide characterization of the laccase gene family in Setaria viridis reveals members potentially involved in lignification. PLANTA 2020; 251:46. [PMID: 31915928 DOI: 10.1007/s00425-020-03337-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 01/02/2020] [Indexed: 05/23/2023]
Abstract
Five laccase genes are potentially involved in developmental lignification in the model C4 grass Setaria viridis and their different tissue specificities suggest subfunctionalization events. Plant laccases are copper-containing glycoproteins involved in monolignol oxidation and, therefore, their activity is essential for lignin polymerization. Although these enzymes belong to large multigene families with highly redundant members, not all of them are thought to be involved in lignin metabolism. Here, we report on the genome-wide characterization of the laccase gene family in the model C4 grass Setaria viridis and further identification of the members potentially involved in monolignol oxidation. A total of 52 genes encoding laccases (SvLAC1 to SvLAC52) were found in the genome of S. viridis, and phylogenetic analyses showed that these genes were heterogeneously distributed among the characteristic six subclades of the family and are under relaxed selective constraints. The observed expansion in the total number of genes in this species was mainly caused by tandem duplications within subclade V, which accounts for 68% of the whole family. Comparative phylogenetic analyses showed that the expansion of subclade V is specifically observed for the Paniceae tribe within the Panicoideae subfamily in grasses. Five SvLAC genes (SvLAC9, SvLAC13, SvLAC15, SvLAC50, and SvLAC52) fulfilled the criteria established to identify lignin-related candidates: (1) phylogenetic proximity to previously characterized lignin-related laccases from other species, (2) similar expression pattern to that observed for lignin biosynthetic genes in the S. viridis elongating internode, and (3) high expression in S. viridis tissues undergoing active lignification. In addition, in situ hybridization experiments not only confirmed that these selected SvLAC genes were expressed in lignifying cells, but also that their expression showed different tissue specificities, suggesting subfunctionalization events within the family. These five laccase genes are strong candidates to be involved in lignin polymerization in S. viridis and might be good targets for lignin bioengineering strategies.
Collapse
Affiliation(s)
- Marcella Siqueira Simões
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua Do Matão, 277, São Paulo, 05508-090, Brazil
| | - Gabriel Garon Carvalho
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua Do Matão, 277, São Paulo, 05508-090, Brazil
| | - Sávio Siqueira Ferreira
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua Do Matão, 277, São Paulo, 05508-090, Brazil
| | - José Hernandes-Lopes
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua Do Matão, 277, São Paulo, 05508-090, Brazil
| | - Nathalia de Setta
- Centro de Ciências Naturais E Humanas, Universidade Federal Do ABC, São Bernardo do Campo, São Paulo, 09606-070, Brazil
| | - Igor Cesarino
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua Do Matão, 277, São Paulo, 05508-090, Brazil.
| |
Collapse
|
26
|
Sakamoto S, Kamimura N, Tokue Y, Nakata MT, Yamamoto M, Hu S, Masai E, Mitsuda N, Kajita S. Identification of enzymatic genes with the potential to reduce biomass recalcitrance through lignin manipulation in Arabidopsis. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:97. [PMID: 32514309 PMCID: PMC7260809 DOI: 10.1186/s13068-020-01736-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 04/09/2020] [Indexed: 05/09/2023]
Abstract
BACKGROUND During the chemical and biochemical decomposition of lignocellulosic biomasses, lignin is highly recalcitrant. Genetic transformation of plants to qualitatively and/or quantitatively modify lignin may reduce these recalcitrant properties. Efficient discovery of genes to achieve lignin manipulation is thus required. RESULTS To screen for new genes to reduce lignin recalcitrance, we heterologously expressed 50 enzymatic genes under the control of a cinnamate 4-hydroxylase (C4H) gene promoter, derived from a hybrid aspen, which is preferentially active in tissues with lignified cell walls in Arabidopsis plants. These genes encode enzymes that act on metabolites in shikimate, general phenylpropanoid, flavonoid, or monolignol biosynthetic pathways. Among these genes, 30, 18, and 2 originated from plants, bacteria, and fungi, respectively. In our first screening step, 296 independent transgenic plants (T1 generation) harboring single or multiple transgenes were generated from pools of seven Agrobacterium strains used for conventional floral-dip transformation. Wiesner and Mäule staining patterns in the stems of the resultant plants revealed seven and nine plants with apparent abnormalities in the two respective staining analyses. According to genomic PCR and subsequent direct sequencing, each of these 16 plants possessed a gene encoding either coniferaldehyde dehydrogenase (calB), feruloyl-CoA 6'-hydroxylase (F6H1), hydroxycinnamoyl-CoA hydratase/lyase (couA), or ferulate 5-hydroxylase (F5H), with one transgenic plant carrying both calB and F6H1. The effects of these genes on lignin manipulation were confirmed in individually re-created T1 transgenic Arabidopsis plants. While no difference in lignin content was detected in the transgenic lines compared with the wild type, lignin monomeric composition was changed in the transgenic lines. The observed compositional change in the transgenic plants carrying calB, couA, and F5H led to improved sugar release from cell walls after alkaline pretreatment. CONCLUSIONS Simple colorimetric characterization of stem lignin is useful for simultaneous screening of many genes with the potential to reduce lignin recalcitrance. In addition to F5H, the positive control, we identified three enzyme-coding genes that can function as genetic tools for lignin manipulation. Two of these genes (calB and couA) accelerate sugar release from transgenic lignocelluloses.
Collapse
Affiliation(s)
- Shingo Sakamoto
- Plant Gene Regulation Research Group, Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Naofumi Kamimura
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188 Japan
| | - Yosuke Tokue
- Plant Gene Regulation Research Group, Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188 Japan
| | - Miyuki T. Nakata
- Plant Gene Regulation Research Group, Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
- Present Address: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192 Japan
| | - Masanobu Yamamoto
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 Japan
| | - Shi Hu
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 Japan
| | - Eiji Masai
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188 Japan
| | - Nobutaka Mitsuda
- Plant Gene Regulation Research Group, Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Shinya Kajita
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 Japan
| |
Collapse
|
27
|
Dixon RA, Barros J. Lignin biosynthesis: old roads revisited and new roads explored. Open Biol 2019; 9:190215. [PMID: 31795915 PMCID: PMC6936255 DOI: 10.1098/rsob.190215] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 10/30/2019] [Indexed: 12/31/2022] Open
Abstract
Lignin is a major component of secondarily thickened plant cell walls and is considered to be the second most abundant biopolymer on the planet. At one point believed to be the product of a highly controlled polymerization procedure involving just three potential monomeric components (monolignols), it is becoming increasingly clear that the composition of lignin is quite flexible. Furthermore, the biosynthetic pathways to the major monolignols also appear to exhibit flexibility, particularly as regards the early reactions leading to the formation of caffeic acid from coumaric acid. The operation of parallel pathways to caffeic acid occurring at the level of shikimate esters or free acids may help provide robustness to the pathway under different physiological conditions. Several features of the pathway also appear to link monolignol biosynthesis to both generation and detoxification of hydrogen peroxide, one of the oxidants responsible for creating monolignol radicals for polymerization in the apoplast. Monolignol transport to the apoplast is not well understood. It may involve passive diffusion, although this may be targeted to sites of lignin initiation/polymerization by ordered complexes of both biosynthetic enzymes on the cytosolic side of the plasma membrane and structural anchoring of proteins for monolignol oxidation and polymerization on the apoplastic side. We present several hypothetical models to illustrate these ideas and stimulate further research. These are based primarily on studies in model systems, which may or may not reflect the major lignification process in forest trees.
Collapse
Affiliation(s)
- Richard A. Dixon
- Hagler Institute for Advanced Studies and Department of Biological Sciences, Texas A&M University, College Station, TX, USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203-5017, USA
| | - Jaime Barros
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203-5017, USA
| |
Collapse
|
28
|
Volpi E Silva N, Mazzafera P, Cesarino I. Should I stay or should I go: are chlorogenic acids mobilized towards lignin biosynthesis? PHYTOCHEMISTRY 2019; 166:112063. [PMID: 31280091 DOI: 10.1016/j.phytochem.2019.112063] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 06/18/2019] [Accepted: 06/30/2019] [Indexed: 05/09/2023]
Abstract
Chlorogenic acids (CGAs) and the biopolymer lignin are both products of the phenylpropanoid pathway. Whereas CGAs have been reported to play a role during stress responses, lignin is a major component of secondary cell walls, providing physical strength and hydrophobicity to supportive and water-conducting tissues. Because the chemical structure of CGAs largely resembles those of some lignin intermediates and because CGAs can be converted back to hydroxycinnamoyl-CoAs in vitro, CGAs have been considered authentic intermediates of the lignin biosynthetic pathway. However, it is still unclear whether and how the CGA pool can be channeled towards the production of lignin monomers in response to developmental or environmental signals. Comprehensive studies on the catalytic activity of recombinant enzymes together with functional characterizations in planta have been very useful in understanding the potential interdependence between these two metabolic routes. Here we present the current understanding on CGA metabolism and discuss the biochemical and molecular evidence of the metabolic re-routing of CGAs towards lignin.
Collapse
Affiliation(s)
- Nathalia Volpi E Silva
- Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Paulo Mazzafera
- Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil; Department of Crop Science, College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, SP, Brazil
| | - Igor Cesarino
- Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão 277, CEP, 05508-090, São Paulo, SP, Brazil.
| |
Collapse
|
29
|
Vaahtera L, Schulz J, Hamann T. Cell wall integrity maintenance during plant development and interaction with the environment. NATURE PLANTS 2019; 5:924-932. [PMID: 31506641 DOI: 10.1038/s41477-019-0502-0] [Citation(s) in RCA: 144] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/23/2019] [Indexed: 05/18/2023]
Abstract
Cell walls are highly dynamic structures that provide mechanical support for plant cells during growth, development and adaptation to a changing environment. Thus, it is important for plants to monitor the state of their cell walls and ensure their functional integrity at all times. This monitoring involves perception of physical forces at the cell wall-plasma membrane interphase. These forces are altered during cell division and morphogenesis, as well as in response to various abiotic and biotic stresses. Mechanisms responsible for the perception of physical stimuli involved in these processes have been difficult to separate from other regulatory mechanisms perceiving chemical signals such as hormones, peptides or cell wall fragments. However, recently developed technologies in combination with more established genetic and biochemical approaches are beginning to open up this exciting field of study. Here, we will review our current knowledge of plant cell wall integrity signalling using selected recent findings and highlight how the cell wall-plasma membrane interphase can act as a venue for sensing changes in the physical forces affecting plant development and stress responses. More importantly, we discuss how these signals may be integrated with chemical signals derived from established signalling cascades to control specific adaptive responses during exposure to biotic and abiotic stresses.
Collapse
Affiliation(s)
- Lauri Vaahtera
- Department of Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Julia Schulz
- Department of Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thorsten Hamann
- Department of Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
| |
Collapse
|
30
|
Chanoca A, de Vries L, Boerjan W. Lignin Engineering in Forest Trees. FRONTIERS IN PLANT SCIENCE 2019; 10:912. [PMID: 31404271 PMCID: PMC6671871 DOI: 10.3389/fpls.2019.00912] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 06/27/2019] [Indexed: 05/19/2023]
Abstract
Wood is a renewable resource that is mainly composed of lignin and cell wall polysaccharides. The polysaccharide fraction is valuable as it can be converted into pulp and paper, or into fermentable sugars. On the other hand, the lignin fraction is increasingly being considered a valuable source of aromatic building blocks for the chemical industry. The presence of lignin in wood is one of the major recalcitrance factors in woody biomass processing, necessitating the need for harsh chemical treatments to degrade and extract it prior to the valorization of the cell wall polysaccharides, cellulose and hemicellulose. Over the past years, large research efforts have been devoted to engineering lignin amount and composition to reduce biomass recalcitrance toward chemical processing. We review the efforts made in forest trees, and compare results from greenhouse and field trials. Furthermore, we address the value and potential of CRISPR-based gene editing in lignin engineering and its integration in tree breeding programs.
Collapse
Affiliation(s)
- Alexandra Chanoca
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Lisanne de Vries
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Wout Boerjan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| |
Collapse
|
31
|
Engelsdorf T, Kjaer L, Gigli-Bisceglia N, Vaahtera L, Bauer S, Miedes E, Wormit A, James L, Chairam I, Molina A, Hamann T. Functional characterization of genes mediating cell wall metabolism and responses to plant cell wall integrity impairment. BMC PLANT BIOLOGY 2019; 19:320. [PMID: 31319813 PMCID: PMC6637594 DOI: 10.1186/s12870-019-1934-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 07/10/2019] [Indexed: 06/01/2023]
Abstract
BACKGROUND Plant cell walls participate in all plant-environment interactions. Maintaining cell wall integrity (CWI) during these interactions is essential. This realization led to increased interest in CWI and resulted in knowledge regarding early perception and signalling mechanisms active during CWI maintenance. By contrast, knowledge regarding processes mediating changes in cell wall metabolism upon CWI impairment is very limited. RESULTS To identify genes involved and to investigate their contributions to the processes we selected 23 genes with altered expression in response to CWI impairment and characterized the impact of T-DNA insertions in these genes on cell wall composition using Fourier-Transform Infrared Spectroscopy (FTIR) in Arabidopsis thaliana seedlings. Insertions in 14 genes led to cell wall phenotypes detectable by FTIR. A detailed analysis of four genes found that their altered expression upon CWI impairment is dependent on THE1 activity, a key component of CWI maintenance. Phenotypic characterizations of insertion lines suggest that the four genes are required for particular aspects of CWI maintenance, cell wall composition or resistance to Plectosphaerella cucumerina infection in adult plants. CONCLUSION Taken together, the results implicate the genes in responses to CWI impairment, cell wall metabolism and/or pathogen defence, thus identifying new molecular components and processes relevant for CWI maintenance.
Collapse
Affiliation(s)
- Timo Engelsdorf
- Institute for Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 5 Høgskoleringen, 7491 Trondheim, Norway
- Present address: Division of Plant Physiology, Department of Biology, Philipps University of Marburg, 35043 Marburg, Germany
| | - Lars Kjaer
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, SW72AZ UK
- Present address: Sjælland erhvervsakademi, Breddahlsgade 1b, 4200 Slagelse, Zealand Denmark
| | - Nora Gigli-Bisceglia
- Institute for Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 5 Høgskoleringen, 7491 Trondheim, Norway
- Present address: Laboratory of Plant Physiology, Wageningen University and Research, Wageningen, 6708PB The Netherlands
| | - Lauri Vaahtera
- Institute for Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 5 Høgskoleringen, 7491 Trondheim, Norway
| | - Stefan Bauer
- Energy Biosciences Institute, University of California, 120A Energy Biosciences Building, 2151 Berkeley Way, MC 5230, Berkeley, CA 94720-5230 USA
- Present address: Zymergen, Inc, 5980 Horton St, Suite 105, Emeryville, CA 94608 USA
| | - Eva Miedes
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo- UPM, Pozuelo de Alarcón, 28223 Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Alexandra Wormit
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, SW72AZ UK
- Present address: RWTH Aachen, Institute for Biology I, Worringerweg 3, D-52056 Aachen, Germany
| | - Lucinda James
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, SW72AZ UK
- Present address: ADAS, Battlegate Road, Boxworth, Cambridge, CB23 4NN UK
| | - Issariya Chairam
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, SW72AZ UK
- Present address: ADAS, Battlegate Road, Boxworth, Cambridge, CB23 4NN UK
- Present address: Department of Nuclear Safety and Security, International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria
| | - Antonio Molina
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo- UPM, Pozuelo de Alarcón, 28223 Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Thorsten Hamann
- Institute for Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 5 Høgskoleringen, 7491 Trondheim, Norway
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, SW72AZ UK
| |
Collapse
|
32
|
Integration of renewable deep eutectic solvents with engineered biomass to achieve a closed-loop biorefinery. Proc Natl Acad Sci U S A 2019; 116:13816-13824. [PMID: 31235605 DOI: 10.1073/pnas.1904636116] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Despite the enormous potential shown by recent biorefineries, the current bioeconomy still encounters multifaceted challenges. To develop a sustainable biorefinery in the future, multidisciplinary research will be essential to tackle technical difficulties. Herein, we leveraged a known plant genetic engineering approach that results in aldehyde-rich lignin via down-regulation of cinnamyl alcohol dehydrogenase (CAD) and disruption of monolignol biosynthesis. We also report on renewable deep eutectic solvents (DESs) synthesized from phenolic aldehydes that can be obtained from CAD mutant biomass. The transgenic Arabidopsis thaliana CAD mutant was pretreated with the DESs and showed a twofold increase in the yield of fermentable sugars compared with wild type (WT) upon enzymatic saccharification. Integrated use of low-recalcitrance engineered biomass, characterized by its aldehyde-type lignin subunits, in combination with a DES-based pretreatment, was found to be an effective approach for producing a high yield of sugars typically used for cellulosic biofuels and biobased chemicals. This study demonstrates that integration of renewable DES with plant genetic engineering is a promising strategy in developing a closed-loop process.
Collapse
|
33
|
Collins MN, Nechifor M, Tanasă F, Zănoagă M, McLoughlin A, Stróżyk MA, Culebras M, Teacă CA. Valorization of lignin in polymer and composite systems for advanced engineering applications – A review. Int J Biol Macromol 2019; 131:828-849. [DOI: 10.1016/j.ijbiomac.2019.03.069] [Citation(s) in RCA: 237] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 03/04/2019] [Accepted: 03/10/2019] [Indexed: 01/30/2023]
|
34
|
Vanholme R, De Meester B, Ralph J, Boerjan W. Lignin biosynthesis and its integration into metabolism. Curr Opin Biotechnol 2019; 56:230-239. [PMID: 30913460 DOI: 10.1016/j.copbio.2019.02.018] [Citation(s) in RCA: 322] [Impact Index Per Article: 64.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/05/2019] [Accepted: 02/22/2019] [Indexed: 11/25/2022]
Abstract
Lignin is a principal structural component of cell walls in higher terrestrial plants. It reinforces the cell walls, facilitates water transport, and acts as a physical barrier to pathogens. Lignin is typically described as being composed of p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) units that derive from the polymerization of the hydroxycinnamyl alcohols, p-coumaryl, coniferyl, and sinapyl alcohol, respectively. However, lignin also derives from various other aromatic monomers. Here, we review the biosynthetic pathway to the lignin monomers, and how flux through the pathway is regulated. Upon perturbation of the phenylpropanoid pathway, pathway intermediates may successfully incorporate into the lignin polymer, thereby affecting its physicochemical properties, or may remain soluble as such or as derivatized molecules that might interfere with physiological processes.
Collapse
Affiliation(s)
- Ruben Vanholme
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Barbara De Meester
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - John Ralph
- Department of Energy, Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, Madison, WI 53726, USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Wout Boerjan
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.
| |
Collapse
|